Hydraulic power apparatus



Jan. 2 5, 1949. BRODEUR I 2,460,058

' HYDRAULIC POWER APPARATUS Filed April 26, 1946 2 Sheets-Sheet 1 Filed April 26, 1946 R M. BRODEUR HYDRAULIC POWER APPARATUS 2 Sheets-Sheet 2 66 5e 66" I I 64 1 6-E I 6 1 .56 5s 54 22 5 58 1272262117702: Raberi/M.B2wdeur.

Patented Jan. 25, 1949 HYDRAULIC rowan APPARATUS Robert M. Brodeur, Worcester, Mass., assignor to Parker Manufacturing Company, Worcester, Mass., a corporation of Massachusetts Application April 26, 1946, Serial No. 665,129

Claims.

This invention relates to a hydraulic power system wherein a continuously running pumpforces fluid through the system and valve mechanism provides for selectively exhausting the discharge to the intake of the pump or operatively connecting the pump to a fluid operated mechanism, and the object is to provide an improved construction for a mechanism'of this nature and one wherein the working fluid is continuously purified by filtration.

My invention will be well understood by reference to the following description of the illustrative embodiment thereof shown by way of example in the accompanying drawings, wherein:

Fig. 1 is a part vertical section and part front elevation, partly broken away, of the power mechanism with hydraulic mechanisms diagrammatically illustrated in connection therewith;

Figs. 2 and 3 are enlarged sections on the lines 2- -2 and 3-3 of Fig. 1 respectively; and

Figs. 4 and 5 are sections on a larger scale than Fig. 1 on the lines 4 -'-4 and 5-5 of that figure respectively.

The construction herein shown is a unitary assemblage which comprises a pump casing ill, the pump indicated at l2 being a gear pump, conveniently and desirably of the kind illustrated in the patent to Davis 2,206,079, on which pump casing is mounted and secured a valve casing [4 on which in turn is mounted a container [6 which in the present instance is divided by a partition l8 into a main chamber 20 at the right, which I may term a reservoir, and an auxiliary chamber 22 on the left constituting a filtering chamber. While for convenience I have referred to a reservoir, in the construction shown the system is designed to be entirely filled with working fluid (oil) and the so-called reservoir is from one point of view a conveniently enlarged connection between the exhaust manifold 24 of the valve and the suction side of the pump.

The detailed construction of the piston valve herein illustrated forms no part of the present invention and does not require description in detail. It will be sufiicient to say that its longitudinal adjustment provides for selective diversion of fluid from the discharge of the pump through suitable passages to pipes 26 leading to hydraulic mechanisms 28 to be operated, herein shown diagrammatically as double-acting hydraulic cylinders, and the exhaust of fluid therefrom to the exhaust manifold. When the valve is in the neutral position shown in Fig. 1, the fluid passes from the discharge 30 of the pump directly to the exhaust manifold. Therefore the pump may run continuously under power whether the hydraulic mechanisms are being operated or not. Herein the fluid passes from the exhaust manifold through ports 32 in the piston heads and a central passage 34 in the valve to the passage 36 in the valve casing communicating with the exhaust manifold 24. Herein the fluid passes from the exhaust manifold 24 through port 38 into the reservoir 20, circulates therein around baiiies 40 and passes therefrom through port 42 to a passage 44 in the valve casing l4 which communicates with the suction intake 46 of the pump.

In accordance with the invention a fractional part only of the pump discharge is diverted through a filter proper and thence returned to the system. This occurs continuously and the entire volume of fluid is therefore treated within a brief time. Herein a passage 48 opens from the discharge 30 of the pump and delivers fluid through a passage 50 traversing the valve casing which leads to a metering orifice 52 of restricted diameter (see Fig. 2) in the bottom of the filtering chamber 22, the oil being discharged in the present instance through a standpipe 54 in that chamber extending about half-way up in the height thereof and providing a dirt trap in the bottom of the chamber. The size of the orifice 52 determines what fraction of the discharge of the pump is diverted therethrough.

Referring now more particularly to Figs. 4 and 5, in the embodiment of the invention shown two filtering elements are provided, of a form not new as such, they being cylindrical masses of loosely twisted textile yarns or rovings 56 wound in themanner of a cop on a central support 58 of moderately coarse wire netting. They are positioned in the chamber 22 by means of annular ridges 60 and 62 respectively on the bottom of the chamber and on a removable cover 64 therefor, which ridges seat on the ends of the wound cylindrical mass, forming a joint therewith. The filtering flow of oil is from the exterior of the cylindrical masses to the hollow interior thereof and the flow leaves the filtering chamber through the central pipe connections 66 and goes through piping 68 back to the reservoir. If the metering restriction 52 is sufiiciently small, it will reduce the pressure on the filter provided there is relatively free discharge from the further side of the latter. Under certain conditions, however, a relatively large metering opening might be desirable to avoid the possibility of clogging with dirt, and in this case the pressure of the fluid passing through the opening might place an undue strain on the filter. In such instance the .lfi-covers. the entire container Iii.

specific construction illustrated in the drawings may be resorted to wherein at a suitable point in the return line, herein at the discharge to the While I have described a so-called reservoir 2 and a filtering chamber 22 as parts. of a. single container IE, it will be seen from Fig. 1 that the two are provided with separate; covers 64- and- 1.2

respectively. By breaking the pipe connection. .58 the cover 64 may be removed for access to the filter without otherwise disturbing the system.

The cover 52 is here shown as provided with a suitable filler opening 1 3 and an air ventlfi is installed in the pipe connection 68. A top lid I am aware that the invention may be'embodied in. other specific. forms without departing from the spirit or essential attributesthereof, andI therefore. desire the present embodiment to be considered in. all respects as'illustrative and not restrictive, as is in fact clear in several matters from the descriptionitself. Reference. is to be had to the appended claims to indicate those principles. of the invention exemplified by the particular embodiment described and which I desire to secure to Letters Patent.

I claim: r I

1. In a. hydraulic system wherein a continuously running pump forcesv fiuid through the system and valve mechanism provides for selectively exhausting the discharge to the intake of the. pump or operatively connecting the pump to a fluidoperated apparatus, in combination with said parts a bypass from thedelivery side of the pump around the valvev mechanism having a filter therein, a metering port at'the inlet side of. the bypass to pass a fractional portion only oi-the; discharge of thepump, and means at the discharge-side of the bypass for creating a back i pressure supportingthe filter.

2. A. hydraulic power system comprising a pump, a valve. housing, a reservoir, passageways in the housing between the reservoir and the intake and exhaust sides of the pump respec tively, passageway-s in the housing for controlling the flowof fluid for a mechanism to be operated and valves selectively controlling the passageways, a. by-pass around the valve system between the discharge side of the pump and the reservoir including a ch-amber'divided by a filter, the bypass at its intake end providing for the passage of a fractional portion only of the discharge of the pump, and means at the discharge side of r 4 the by-pass for creating a back pressure supporting the filter.

3. A hydraulic 'powersystem comprising a pump, a valve housing mounted thereon, a receptacle on the housing divided into main and auxiliary open-topped chambers, separate covers for the chambers, passageways in the housing between the main chamber and. the intake and discharge sidesoi the pumprespectively, passageways in the housing for controlling the flow of fluid for a mechanism to be operated, valves selectively controlling the passageways, a filtering layer dividing the auxiliary chamber, a passageway independent of the other passageways recited'between the discharge side of the pump and one'side of the filtering layer embodying a. 7

portion of small cross-section to pass a fractional portion only of the discharge of the pump, and a connection between the other side of the filtering layer and the mainthamber,

a. A hydraulic power system' comprising a pump, ayalve housingmounted thereon, a container on the. valve housing, passageways in the housing between said container and the intake and discharge sides of the pump respectively, passageways in the housing for control-ling the flow of fluid for a mechanism tobe operated and valves selectively controlling the passageways, a chamber adjacent, the container, which chamber is divided by a filter, a passage through the housing from the discharge side of the pump to one side of the filterembodying a restricted port,

and a connection from the other side of the filter the filterin layer being in communication with the intake side of the pump th-rough a connection effective to maintain a back. pressure on the filtering layer.

' r ROBERT M. BRODEUR.

REFERENCES CITED The following'references are of record in the file of this patent: .7

UNrrEn STATES, PATENTS Number Name Date 2,242,807 Austin May 20,-1941 2,268,653" 7 Flowers Jan. 6, 1942 

